I use to own a 7mm Rem Mag and handloaded for it for many years. I would recommend adjusting the resizing die down until it touches the shellholder. The reason being that if I didn't, they would be a little hard to chamber. I also found that I needed to trim my casing after the second shot. I most likely would still have a 7mm Rem Mag but used it for a wildcat project, my 8mm Grizzly.